Biomechanical properties of soft tissues

Viscoelasticity is the primary mechanical property of bio-soft tissues. It has been widely applied in basic research of biological tissues including cornea, lung, heart and blood vessels. Along with the development of tissue engineering research, the evaluation of soft tissue viscoelasticity is becoming more and more important. In this paper, using the Whittaker function, we give an approximate power series of the exponential integralE ₁(X) and the parametersC, ?₁ and ?₂ of the generalized relaxation functionG(t) and generalized creep functionJ(t). With expanded skin as an example, the relationship between stress relaxation, creep and stress-strain finite deformation are studied.     

细胞粘附的生物力学研究进展

介绍了细胞粘附的生物力学领域的进展和基本概念,对生物力学中这一新领域的研究进行了评价．同时对力学分析方法和试验方法给予评论,而这些方法示明：细胞粘附的生物力学研究趋势是从细胞力学至分子力学,而在不久将来将进入微观力学范畴     

药物透皮参数的估计与研究

参考透皮给药的大量实验数据,选择一种非线性回归模型作为相应的数学模型,并通过这一模型中的透皮系数作为被估计的参数完成了这一工作,同时给出了对20种药物的不同渗透系数的估计．最后的讨论中发现,这一工作进一步支持了将皮肤视作单层渗透膜的理论．     

眼固体生物力学研究

眼是光转换的视觉器官, 通常考虑将其作为一个生物力学结构. 眼睛是眼内肌和眼外肌产生压力的系统, 具有复杂的内血管系统,产生流体和溶合物的传导系统. 从生物力学角度看, 眼存在固体生物力学、流体生物力学和生物传输等问题. 本综述中, 介绍眼睛有意义的生物固体力学各方面研究成果及尚待解决的问题, 其研究对象为巩膜、角巩膜、角膜、视网膜、筛板以及眼调节和老花. 回顾测量巩膜力学性质和角巩膜应力－应变性质模型的有关研究成果, 然后论述这些研究成果的应用.巩膜力学另一重要应用是对近视的了解, 即眼的轴长过长使长距离光线不能够清晰聚焦于视网膜而引起近视. 角膜生物力学一个显著的应用是预测激光切开剖面手术, 它将使屈光角膜手术达到最优的术后视敏度. 筛板是眼中最具有生物力学研究兴趣的组织之一, 它是跨过巩膜管的多孔的结缔组织. 推导出青光眼的视神经病的力学理论.证据表明围绕着睫状肌的结蹄组织发生变化可能妨碍它的自由收缩的能力, 因此老花的病理学原因可能是多因素的.      

角质层渗透性质的有限元数值模拟计算

角质层是皮肤屏障作用的最主要部分，它决定了外界物质对皮肤的渗透情况．在假设角质层细胞为一种三维的十四面体（物理学经典的tetrakaidecahedron体）的情况下，利用有限元法对角质层渗透性质进行了数值模拟研究．为此，首先完成了对角质层空间结构的网格拆分，拆分过程分两步进行：1．对角蛋白细胞的网格拆分；2．对角蛋白细胞周围的网状脂质体的网格拆分．在数值模拟过程中，则用有限元法得到方程离散的格式，用多重网格算法降低高频误差，提高计算精度．最后，给出了数值模拟结果的可视化效果图．     

FINITE ELEMENT METHOD ON NUMERICAL SIMULATION OF STRATUM CORNEUM''''S PENETRATION PROPERTY

How the outer substance could penetrate through the skin lies in the stratum corneum, because it is the main barrier in the multi-layers of the skin. Supposing the keratin cell with a special geometry as tetrakaidecahedron, the penetration property of stratum corneum was the key problem which was numerically simulated with finite element method. At first the discretization of the stratum corneum region was given in two steps: first, the discretization of the keratin cell; second, the discretization of fattiness that surrounds the keratin. Then there was the work of numerical simulation. In this procedure, the finite element method and the multi-grid method were used. The former was to obtain the discretization of basic elements; the latter was to decrease the high frequency error. At last the visualization of the numerical simulation was shown.     

FINITE ELEMENT METHOD ON NUMERICAL SIMULATION OF STRATUM CORNEUM＇S PENETRATION PROPERTY

How the outer substance could penetrate through the skin lies in the stratum corneum, because it is the main barrier in the multi-layers of the skin. Supposing the keratin cell with a special geometry as tetrakaidecahedron, the penetration property of stratum corneum was the key problem which was numerically simulated with finite element method. At first the discretization of the stratum corneum region was given in two steps： first, the discretization of the keratin cell; second, the discretization of fattiness that surrounds the keratin. Then there was the work of numerical simulation. In this procedure, the finite element method and the multi-grid method were used. The former was to obtain the discretization of basic elements; the latter was to decrease the high frequency error. At last the visualization of the numerical simulation was shown.     

确定在体皮肤能量耗散数的方法

本文描述了激励、检测在体皮肤谐振频率的方法。根据幅频曲线计算出皮肤的能量耗散数。获得了不同年龄的皮肤耗散数。对皮肤受乳膏和酒精处理后,利用该法对能量耗散数的影响也进行了评价。     

动脉壁静态力学性质的实验

生命体材料的力学性质具有其特殊性和复杂性．因而,对其进行力学实验研究也具有从实验设计、实验方法到实验技术的特殊性和复杂性．本文详尽地研究了动脉壁三维静态力学实验的方法和技术：进行了四只白兔颈动脉的静态力学性质实验;得到了性态较好的实验结果     

红细胞聚集的生物力学基础

红细胞聚集是一种细胞间的非特异粘附．从宏观角度讲,它是一种热力学过程;由不分散的单个细胞发展为三维网状结构．而从细观上看则是一种细胞膜间有大分子参与的弱相互作用．本文对红细胞的聚集形式模型从生物力学角度进行了综述．